I've had my crowntail, Khonsu, for several months now. He was fairly young and in good shape when I got him. About a month ago, I moved him from a smaller tank into a large 5.5 gallon tank. It's heated (75 deg.) and cycled, with several plastic plants and a few other decorations. Ph is 7.0, and I've ordered a kit to test ammonia and the like. I do 50% water changes once a week. He has a peppered corydora as a tankmate. (I know they are usually schooling fish, but he does fine on his own. Betta rarely bothers him.) Recently, the rays on Khonsu's fins have started to look a little more withered than usual. He's still behaving as usual, but I've noticed that two of his rays have lost about half the bottom portion. I think he may have fin rot, but it's very difficult to tell with crowntails. I have Maracyn I and II on hand (which I've read is sufficient if the fin rot is slight.), and Melafix (that I am very hesitant to use...it killed two of my lovely halfmoons.) I use a pinch of aquarium salt and sufficient water conditioner with every water change. I've included a picture, but it's a little hard to see his fins. Khonsu is very friendly and wanted to smile for the camera. Should I go ahead and start medicating with the Maracyn to get a jump on the rot before it gets worse?

You don't need meds to treat fin rot. It's hard to tell from the pic if he has it but it kind of looks like it. Fin rot is typically a water quality issue. When you say the tank is cycled, how long has it been running & how did you cycle it? Having 2 fish in a 5.5 IMO is too much. You may have an ammonia problem but without testing the water you won't know. I'm assuming you ordered a liquid water test kit? Aq salt is not needed for every water change unless you are specifically treating for something like fin rot but its only supposed to be used for 10 days. I would up the water changes to 50% at least twice a week until you can properly test your water. I would also up the temp a degree or two, I prefer to keep my tanks at 78 & that's what most suggest is a good temp.

You don't need meds to treat fin rot. It's hard to tell from the pic if he has it but it kind of looks like it. Fin rot is typically a water quality issue. When you say the tank is cycled, how long has it been running & how did you cycle it? Having 2 fish in a 5.5 IMO is too much. You may have an ammonia problem but without testing the water you won't know. I'm assuming you ordered a liquid water test kit? Aq salt is not needed for every water change unless you are specifically treating for something like fin rot but its only supposed to be used for 10 days. I would up the water changes to 50% at least twice a week until you can properly test your water. I would also up the temp a degree or two, I prefer to keep my tanks at 78 & that's what most suggest is a good temp.

It's been running over a month now. I only cycled a week or so before introducing him...he was getting very unhappy in his previous tank. I did order a liquid test kit. I'll use the salt for a month, then stop for a month. That's what I did in his previous tank just to keep him from getting anything. Test kit should be here Thursday, but I'll give the tank a good cleaning tomorrow. Thanks.

I finally got pictures of his sides...as good of a picture as I'm going to get at least. His fins have always been a little curled and tattered on the ends. It's the missing pieces I'm more worried about. (You can kind of see it in the first picture near the long split in his tail.

Running a tank a month without providing an ammonia source unfortunately does not cycle a tank. I would suspect you have some ammonia issues due to the tank not being properly cycled & having 2 fish in a 5.5. As I previosly stated I would do at least 2 50% water changes with a good gravel cleaning per week until you can get your water tests done properly.

You claim to use PLASTIC decorations! Incase you were misinformed (not to be rude), plastic tears the bettas fins. Your state of ripped fins seems to be because of ripped fins. I feel for your situation! My crowntail, see avatar, has fin damage. And it started out looking like this.